Dereferencing NULL

[ron%brl-vgr at sri-unix.UUCP]

From:      Ron Natalie <ron at brl-vgr>

Actually, on a VAX running BSD dereferencing NULL had best give you
zero.  A large amount of the code depends on it (I'm not saying this
is a good idea, it's just the way it is).  For example, the only reason
you can use a zero as an argument to IOCTL where it is expecting either
a zero or a pointer to some number is not because it ever checks for
null pointers but because it happens to work because *0 == 0.

-Ron